The difference between SI and CI for 2 years @ 20% per annum is Rs 8. What is the principal?

The correct option is A 200

Difference between SI and CI for $2$ years $=P{\left[\frac{R}{100}\right]}^2$

$8=P{\left[\frac{20}{100}\right]}^2$

$\Rightarrow 8=P{\left[\frac{1}{5}\right]}^2$

$\Rightarrow P=8\times 25=Rs.200$

$\therefore$ Principal$=Rs.200$